D69U Radiator Leakage

The engine cover attachment includes 5 bolts that go into the radiator. One of the bolts was drilled too deeply causing leakage See photos. How should this be repaired or fixed? For example, can the hole be welded closed and then re-drilled? Other, perhaps simpler fixes?

Don

Thread sealant

Try a sealing washer:

https://www.mcmaster.com/standard-sealing-washers

Is there any risk of that bolt seizing if using thread sealant cc?

Usually it's the other way around, sealants help prevent rust in the threads by keeping coolant and rainwater out.

[quote="clark4u9u"]The engine cover attachment includes 5 bolts that go into the radiator. One of the bolts was drilled too deeply causing leakage See photos. How should this be repaired or fixed? For example, can the hole be welded closed and then re-drilled? Other, perhaps simpler fixes?

Don[/quote]
A couple of things :
A blind thread repair insert installed with loctite.
A stud installed with locktite.
Your bolt installed with loctite high performance thread . sealant.
You could clean the hole out with brake cleaner & seal the end of the hole with JB Weld, etc.
If you don't care about using the bolt, how about a set screw in the hole with sealant?

For me, I would use a method to avoid the hassle with resealing every time I needed to access the panel.